The invention relates to a plastic housing for locating an electrical printed circuit board.
Increasingly, and in particular in the automotive industry, electronic modules are being made with plastic housings because, apart from their relatively simple and low-cost manufacture, they are in particular considerably lighter, and this in turn results in lower fuel consumption. For fastening the plastic housing to a metal carrier body, the plastic housing generally has a mounting flange with an opening. However, since the mounting flange of the plastic housing can very easily be deformed or damaged at the opening due to forces applied at the time of mounting, for instance when driving in screws or riveting, a metal insert is used in order to increase the transmissible forces, as described for example in DE 39 16 899 A1. Furthermore, DE 41 31 779 A1 describes a screwed fastening where a bush for a recessed-collar head screw is situated in a housing cover.
It is a disadvantage of metal inserts that a chemical contact junction can be created at the junction between metal insert and metal carrier body if these are made of different metals or metal alloys. A voltage, the magnitude of which depends on the electrochemical series, builds up between these as a result of moisture and electrolyte and this can lead to faults in electrical components inside the plastic housing or permanent damage to the junction point. It is known from the Code of Practice 1.031 of the Corrosion Working Group that plastic washers and insulating binders are used for this case, as described for example in the utility patent G 93 03 091 U1.
However, such additional plastic components call for additional placing, adjustment and assembly steps which considerably increase the cost of assembly.